The world's first geared CVT, capable of smoothly changing ratios between zero and high gear - Alter Ego / RatioZero
Posted on 12/09/2024 8:28:32 PM PST by Red Badger
The efficiency of a tooth-on-tooth geared transmission, with the smoothly variable gear ratios of a CVT – minus the belt friction and capable of going all the way down to a zero ratio without needing a clutch. That's a 'holy grail' level promise!
Italian company Alter Ego, led by mechanical and automation engineer Edyson Pavilcu and assisted by kinematic studies undertaken at the Milan Technical University, says it's prototyped a beautifully complex new mechanism – the world's first geared CVT – that's 10% more efficient than a regular belted CVT.
Indeed, the efficiency is on par with some manual transmissions, while offering the ability to smoothly adjust gear ratios from zero all the way up to overdrive, whether the wheels and/or crank are turning or not.
A quick manual vs CVT transmission primer
Why is this a big deal? Well, transmissions are designed to let a drive system – be that an engine, an electric motor or a set of cyclists' legs turning a crank – operate at its optimal speed for efficient torque delivery, while adjusting the gear ratio between the drive system and the wheels to give just the right leverage for the current speed and situation.
Manual transmissions are very efficient, meshing metal gears together to deliver between 95-98% of input power to the other side. But you can only have as many gears as you can fit in the box, and multi-clutch systems aside, you have gaps in the power delivery where you need to friction-clutch out of gear then back in to the next one. When in gear, your ratio is locked, so your engine speed has to vary as you accelerate or decelerate. You can stay close to your ideal engine speed for the conditions, but not dead on.
(Excerpt) Read more at newatlas.com ...
The world's first geared CVT, capable of smoothly changing ratios between zero and high gear - Alter Ego / RatioZero
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My Honda PCX 150 uses a CVT.
Saving for later
This is just what I want. Something really complicated. Nobody can fix or rebuild it. There’s no extra ones available in case mine goes South because all available goes to the assembly line for new vehicles. I can just sell my vehicle to a scrap yard.
Some.
CAFE standards have been making it difficult for major automakers NOT to go CVT on many vehicles. So now we have transmissions that fail before spark plugs, weird. I’ll take a Mopar three speed torqueflite. Whatever is in my Toyota Avalon works fine, too. Anything more than six speeds is overkill.
I’ll look into this when my 2013 Toyota Tacoma dies around 2040.
I hope this takes off for the people who want autos as the current back of “belt driven” CVTs are horrible. I had a Toyota CH-R rental with one, and it was like you had to kick down to passing gear every time you needed to speed up.
PING!......................
From lack of real interest, I still notice more than a few car makers are having major trouble with their CVT.
Datsun being a major one with bad CVTs..
Been a manual trans guy for as long as I been driving.
Only went auto with my Toyota 4Runners.
Think the wife’s Subaru has a CVT, not sure, and I rarely drive the thing.
OK, Eeyore. LOL
CVT in their current form are crap.. which is one of the Reasona Honda’s are now garbage.
Belt CVTs cannot last, they simply wear out.
Is this geared model goes into production then maybe CVT’s will see the reliability and longevity that cars have had… but belt CVT’s are just a system that can’t last 200-300k. They will fail long before they get the ther
I detect a hint of cyno-sarcasm in your reply...?
It does look gawdawful complicated.
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CAFE standards seriously need to be rolled back. They are why cars have become more expensive and simultaneously less reliable.
I am sick and tired of the auto industry just rolling over without a fight thinking they can keep shoving the costs and consequences off on the consumer.
CAFE standards need to die.
CVT = Continuously variable transmission
Walk behind that fer a smile (er, mile) or two. A smoothly varying, well lubricated Italian analog transmission system.
Well, it could be complicated and British.
Although my college kid has a 11 year old passed down Range Rover with a monster engine and 6 digit miles that looks new and whose problems have been limited to a spark plug that needed to be screwed in better after the dealer changed plugs at 120k miles. BMW really changed their company philosophy.
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